The Ultimate comics are not the first to drop the Shakespeare-speak; Thor actually started out without it in his earliest appearances under Stan Lee. It was added in some time later to make Thor sound more regal or something, but various writers have chosen not to use it throughout Thor's history--most recently, JMS in the current Thor comics.

I don't personally mind the Shakespeare-speak; it's given us such memorable lines as "Ultron, we would have words with thee" in Busiek's Avengers run. But it can make for overly cumbersome dialogue, a shockingly large number of writers have no f***ing clue how to use it properly, and people like Timstuff think it's corny, so I voted no, it should not be in the movie. Thor is relatively obscure to the general public and his world is vastly different from most other major comic book characters'; it's not what you expect to see when someone mentions "this movie's based on a comic book." So the odds are stacked against his movie being a huge success as it is. Anything that can make it more digestible to the general audience, short of betraying the spirit of the classic Thor, is welcome. The fewer obstacles to people enjoying Thor, the better.

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"This I grant to you: You may tell your grandchildren that you stood for a time against the mighty Thor."
- Marvel Heroes